Conveying devices which are magnet-operated or powered by magnets are known in an extremely wide range of configurations from the prior art. Thus, for example, DE 1958177 A1 describes a conveying device with a circulating, endlessly magnetizable conveyor belt and an endless driver chain which acts on the inside of said conveyor belt, is provided with permanent magnets and is driven by a drive device. On the upper side of the conveyor belt, suitable conveying elements which are magnetic, that is to say likewise provided with permanent magnets, are used to convey materials. The problem with all magnet-operated conveying devices is contamination of the permanent magnets. This primarily leads to local changes in the magnetic field. Depending on the level of contamination, it is additionally possible for mechanical faults to the conveying sequence and the conveying speed to occur.